搜索结果: 'methocult media formulations for human hematopoietic cells serum containing'

Cutaneous tuberculosis (CTB) is an infectious disease highly associated with extracellular matrix remodeling and granuloma-driven fibrosis. Fibroblasts play crucial roles in this fibrotic process,but their specific roles in Mycobacterium tuberculosis (Mtb) skin infections remain unclear due to the lack of proper in vitro models. Here,we demonstrate that skin organoids (SKOs) derived from human induced pluripotent stem cells can model CTB infected by Mtb. Single-cell RNA analyses reveal an increase in fibroblasts,upregulation of genes involved in collagen synthesis,and enhanced collagen degradation induced by MMP2 and MMP14 in Mtb-infected SKOs. This is accompanied by the destruction of nerve cells and adipocytes. Importantly,the onset of fibrosis in Mtb-infected SKOs is dependent on the activation of the PI3K-AKT signaling pathway and transcription factor AP1 in fibroblasts. Pharmacological inhibition of PI3K-AKT and AP1 alleviates fibrosis and collagen deposition. Our findings have uncovered distinct alterations in cell populations during Mtb-induced skin fibrosis,highlighting the crucial roles of PI3K-AKT and AP1. The study demonstrates the utility of SKOs for investigating CTB pathogenesis and evaluating potential antifibrotic treatments. Cutaneous tuberculosis is an infectious disease associated with extracellular matrix remodeling and granuloma-driven fibrosis. Here,the authors present an in vitro model of this disease using skin organoids infected with Mycobacterium tuberculosis,and describe infection-induced alterations in specific pathways and cell populations. View Publication

Alternative splicing (AS) is a crucial mechanism contributing to proteomic diversity,which is highly regulated in tissue- and development-specific patterns. Retinal tissue exhibits one of the highest levels of AS. In particular,photoreceptors have a distinctive AS pattern involving the inclusion of microexons not found in other cell types. PROM1 whose encoded protein Prominin-1 is located in photoreceptor outer segments (OSs),undergoes exon 4 inclusion from the 12th post-conception week of human development through adulthood. Exon 4 skipping in PROM1 is associated with late-onset mild maculopathy,however its role in photoreceptor maturation and function is unknown. In this study retinal organoids,a valuable model system,were employed in combination with phosphorodiamidate morpholino oligos (PMOs) to assess the role of exon 4 AS in the development of human retina. Retinal organoids were treated with the PMOs for four weeks after which RT-PCR,western blotting and immunofluorescence analysis were performed to assess exon 4 exclusion and its impact on photoreceptors. The transcriptome of treated ROs was studied by bulk RNA-Seq. Our data demonstrate that 55% skipping of PROM1 exon 4 resulted in decreased Prominin-1 expression by 40%,abnormal accumulation of cones in the basal side of the retinal organoids as well as detectable cone photoreceptor cilium defects. Transcriptomic and western blot analyses revealed decreased expression of cone,inner segment and connecting cilium basal body markers,increased expression of genes associated with stress response and the ubiquitin-proteasome system,and downregulation of autophagy. Importantly,the use of retinal organoids provides a valuable platform to study AS and unravel disease mechanisms in a more physiologically relevant context,opening avenues for further research and potential therapeutic interventions. Together our data indicate that cones may be more sensitive to PROM1 exon 4 skipping and/or reduced Prominin-1 expression,corroborating the pathogenesis of late-onset mild maculopathy. View Publication

SummaryMonocytes are critical to innate immunity,participating in chemotaxis during tissue injury,infection,and inflammatory conditions. However,the migration dynamics of human monocytes under different guidance cues are not well characterized. Here,we developed a microfluidic device to profile the migration characteristics of human monocytes under chemotactic and barotactic guidance cues while also assessing the effects of age and cytokine stimulation. Human monocytes preferentially migrated toward the CCL2 gradient through confined microchannels,regardless of donor age and migration pathway. Stimulation with interferon (IFN)-γ,but not granulocyte-macrophage colony-stimulating factor (GM-CSF),disrupted monocyte navigation through complex paths and decreased monocyte CCL2 chemotaxis,velocity,and CCR2 expression. Additionally,monocytes exhibited a bias toward low-hydraulic-resistance pathways in asymmetric environments,which remained consistent across donor ages,cytokine stimulation,and chemoattractants. This microfluidic system provides insights into the unique migratory behaviors of human monocytes and is a valuable tool for studying peripheral immune cell migration in health and disease. Graphical abstract Highlights•The MAP chip profiles migration of human monocytes under various chemotactic and barotactic cues•Monocytes preferentially migrate toward CCL2 gradients,regardless of migration pathway and donor age•IFN-γ reduces human monocyte chemotaxis,velocity,and CCR2 expression•Human monocytes show biased migration toward low-hydraulic-resistance pathways MotivationCell migration is fundamental to the biological processes that drive health and disease. While in vivo models provide invaluable insights into cell migration within complex biological environments,precise control over the microenvironment and single-cell tracking is essential to deepen our understanding of the fundamental characteristics of cell migration. We present a high-throughput microfluidic platform,termed the migration analysis of peripheral immune cells (MAP) chip,that features four distinct sets of microchannels designed to assess the effects of both chemotactic and barotactic stimuli on cell migration at a single-cell level. By profiling human monocyte migration using the MAP chip,we demonstrated the utility of this device in characterizing migration of human monocytes under diverse conditions. Hall et al. introduce the MAP chip,a microfluidic platform for profiling human monocytes under chemotactic and barotactic guidance cues. It reveals biased migration toward low-hydraulic-resistance pathways,disrupted migration upon cytokine stimulation,and consistent chemotaxis and barotaxis across donor ages—enhancing our understanding of human monocyte migration characteristics. View Publication

The angiotensin-converting enzyme 2 (ACE2) is a primary cell surface viral binding receptor for SARS-CoV-2,so finding new regulatory molecules to modulate ACE2 expression levels is a promising strategy against COVID-19. In the current study,we utilized islet organoids derived from human embryonic stem cells (hESCs),animal models and COVID-19 patients to discover that fibroblast growth factor 7 (FGF7) enhances ACE2 expression within the islets,facilitating SARS-CoV-2 infection and resulting in impaired insulin secretion. Using hESC-derived islet organoids,we demonstrated that FGF7 interacts with FGF receptor 2 (FGFR2) and FGFR1 to upregulate ACE2 expression predominantly in ? cells. This upregulation increases both insulin secretion and susceptibility of ? cells to SARS-CoV-2 infection. Inhibiting FGFR counteracts the FGF7-induced ACE2 upregulation,subsequently reducing viral infection and replication in the islets. Furthermore,retrospective clinical data revealed that diabetic patients with severe COVID-19 symptoms exhibited elevated serum FGF7 levels compared to those with mild symptoms. Finally,animal experiments indicated that SARS-CoV-2 infection increased pancreatic FGF7 levels,resulting in a reduction of insulin concentrations in situ. Taken together,our research offers a potential regulatory strategy for ACE2 by controlling FGF7,thereby protecting islets from SARS-CoV-2 infection and preventing the progression of diabetes in the context of COVID-19. View Publication

Age-related macular degeneration (AMD) affects the retinal pigment epithelium (RPE),a cell monolayer essential for photoreceptor survival,and is the leading cause of vision loss in the elderly. There are no disease-altering therapies for dry AMD,which is characterized by accumulation of subretinal drusen deposits and complement-driven inflammation. We report the derivation of human-induced pluripotent stem cells (hiPSCs) from patients with diagnosed AMD,including two donors with the rare ARMS2/HTRA1 homozygous genotype. The hiPSC-derived RPE cells produce several AMD/drusen-related proteins,and those from the AMD donors show significantly increased complement and inflammatory factors,which are most exaggerated in the ARMS2/HTRA1 lines. Using a panel of AMD biomarkers and candidate drug screening,combined with transcriptome analysis,we discover that nicotinamide (NAM) ameliorated disease-related phenotypes by inhibiting drusen proteins and inflammatory and complement factors while upregulating nucleosome,ribosome,and chromatin-modifying genes. Thus,targeting NAM-regulated pathways is a promising avenue for developing therapeutics to combat AMD. View Publication

Molecular mimicry between microbial and self-components is postulated as the mechanism that accounts for the antigen and tissue specificity of immune responses in postinfectious autoimmune diseases. Little direct evidence exists,and research in this area has focused principally on T cell-mediated,antipeptide responses,rather than on humoral responses to carbohydrate structures. Guillain-Barré syndrome,the most frequent cause of acute neuromuscular paralysis,occurs 1-2 wk after various infections,in particular,Campylobacter jejuni enteritis. Carbohydrate mimicry [Galbeta1-3GalNAcbeta1-4(NeuAcalpha2-3)Galbeta1-] between the bacterial lipooligosaccharide and human GM1 ganglioside is seen as having relevance to the pathogenesis of Guillain-Barré syndrome,and conclusive evidence is reported here. On sensitization with C. jejuni lipooligosaccharide,rabbits developed anti-GM1 IgG antibody and flaccid limb weakness. Paralyzed rabbits had pathological changes in their peripheral nerves identical with those present in Guillain-Barré syndrome. Immunization of mice with the lipooligosaccharide generated a mAb that reacted with GM1 and bound to human peripheral nerves. The mAb and anti-GM1 IgG from patients with Guillain-Barré syndrome did not induce paralysis but blocked muscle action potentials in a muscle-spinal cord coculture,indicating that anti-GM1 antibody can cause muscle weakness. These findings show that carbohydrate mimicry is an important cause of autoimmune neuropathy. View Publication

The basic helix-loop-helix transcription factor achaete-scute complex homologue 1 (ASCL1) is essential for the development of normal lung neuroendocrine cells as well as other endocrine and neural tissues. Small cell lung cancer (SCLC) and non-SCLC with neuroendocrine features express ASCL1,where the factor may play a role in the virulence and primitive neuroendocrine phenotype of these tumors. In this study,RNA interference knockdown of ASCL1 in cultured SCLC resulted in inhibition of soft agar clonogenic capacity and induction of apoptosis. cDNA microarray analyses bolstered by expression studies,flow cytometry,and chromatin immunoprecipitation identified two candidate stem cell marker genes,CD133 and aldehyde dehydrogenase 1A1 (ALDH1A1),to be directly regulated by ASCL1 in SCLC. In SCLC direct xenograft tumors,we detected a relatively abundant CD133(high)-ASCL1(high)-ALDH1(high) subpopulation with markedly enhanced tumorigenicity compared with cells with weak CD133 expression. Tumorigenicity in the CD133(high) subpopulation depended on continued ASCL1 expression. Whereas CD133(high) cells readily reconstituted the range of CD133 expression seen in the original xenograft tumor,CD133(low) cells could not. Our findings suggest that a broad range of SCLC cells has tumorigenic capacity rather than a small discrete population. Intrinsic tumor cell heterogeneity,including variation in key regulatory factors such as ASCL1,can modulate tumorigenicity in SCLC. View Publication

Organoids represent both a potentially powerful tool for the study cell-cell interactions within tissue-like environments,and a platform for tissue regenerative approaches. The development of lung tissue-like organoids from human adult-derived cells has not previously been reported. Here we combined human adult primary bronchial epithelial cells,lung fibroblasts,and lung microvascular endothelial cells in supportive 3D culture conditions to generate airway organoids. We demonstrate that randomly-seeded mixed cell populations undergo rapid condensation and self-organization into discrete epithelial and endothelial structures that are mechanically robust and stable during long term culture. After condensation airway organoids generate invasive multicellular tubular structures that recapitulate limited aspects of branching morphogenesis,and require actomyosin-mediated force generation and YAP/TAZ activation. Despite the proximal source of primary epithelium used in the airway organoids,discrete areas of both proximal and distal epithelial markers were observed over time in culture,demonstrating remarkable epithelial plasticity within the context of organoid cultures. Airway organoids also exhibited complex multicellular responses to a prototypical fibrogenic stimulus (TGF-??1) in culture,and limited capacity to undergo continued maturation and engraftment after ectopic implantation under the murine kidney capsule. These results demonstrate that the airway organoid system developed here represents a novel tool for the study of disease-relevant cell-cell interactions,and establishes this platform as a first step toward cell-based therapy for chronic lung diseases based on de novo engineering of implantable airway tissues. View Publication

Focal malformations of cortical development (FMCDs) account for the majority of drug-resistant pediatric epilepsy. Postzygotic somatic mutations activating the phosphatidylinositol-4,5-bisphosphate-3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of rapamycin (mTOR) pathway are found in a wide range of brain diseases,including FMCDs. It remains unclear how a mutation in a small fraction of cells disrupts the architecture of the entire hemisphere. Within human FMCD-affected brain,we found that cells showing activation of the PI3K-AKT-mTOR pathway were enriched for the AKT3(E17K) mutation. Introducing the FMCD-causing mutation into mouse brain resulted in electrographic seizures and impaired hemispheric architecture. Mutation-expressing neural progenitors showed misexpression of reelin,which led to a non-cell autonomous migration defect in neighboring cells,due at least in part to derepression of reelin transcription in a manner dependent on the forkhead box (FOX) transcription factor FOXG1. Treatments aimed at either blocking downstream AKT signaling or inactivating reelin restored migration. These findings suggest a central AKT-FOXG1-reelin signaling pathway in FMCD and support pathway inhibitors as potential treatments or therapies for some forms of focal epilepsy. View Publication

Staphylococcus aureus is both an important pathogen and a human commensal. To explore this ambivalent relationship between host and microbe,we analysed the memory humoral response against IsdB,a protein involved in iron acquisition,in four healthy donors. Here we show that in all donors a heavily biased use of two immunoglobulin heavy chain germlines generated high affinity (pM) antibodies that neutralize the two IsdB NEAT domains,IGHV4-39 for NEAT1 and IGHV1-69 for NEAT2. In contrast to the typical antibody/antigen interactions,the binding is primarily driven by the germline-encoded hydrophobic CDRH-2 motifs of IGHV1-69 and IGHV4-39,with a binding mechanism nearly identical for each antibody derived from different donors. Our results suggest that IGHV1-69 and IGHV4-39,while part of the adaptive immune system,may have evolved under selection pressure to encode a binding motif innately capable of recognizing and neutralizing a structurally conserved protein domain involved in pathogen iron acquisition. View Publication

Gfi-1B is a transcriptional repressor that is crucial for erythroid differentiation: inactivation of the GFI1B gene in mice leads to embryonic death due to failure to produce differentiated red cells. Accordingly,GFI1B expression is tightly regulated during erythropoiesis,but the mechanisms involved in such regulation remain partially understood. We here identify HMGB2,a high-mobility group HMG protein,as a key regulator of GFI1B transcription. HMGB2 binds to the GFI1B promoter in vivo and up-regulates its trans-activation most likely by enhancing the binding of Oct-1 and,to a lesser extent,of GATA-1 and NF-Y to the GFI1B promoter. HMGB2 expression increases during erythroid differentiation concomitantly to the increase of GfI1B transcription. Importantly,knockdown of HMGB2 in immature hematopoietic progenitor cells leads to decreased Gfi-1B expression and impairs their erythroid differentiation. We propose that HMGB2 potentiates GATA-1-dependent transcription of GFI1B by Oct-1 and thereby controls erythroid differentiation. View Publication